Establishing traffic priorities in a voice over IP network

Abstract

A method and apparatus for establishing traffic priorities in an IP network connected with multiple communication sources is disclosed. Different types of packets such as voice packets and data packets are received for transmission over a single network access link. In order to assure quality voice transmissions, voice packets are given priority over data packets by limiting a transmission rate from a data input queue whenever voice packets are detected in a voice input queue. Different combinations of interleaved voice and data packets help to alleviate packet congestion while maintaining priority for voice packets. In one aspect of the invention, priority for voice packets is further accomplished by limiting the size of data packet frames. In some instances when no voice packets are awaiting transmission, data packets are transmitted at a maximum rate in order to make full use of the network access link bandwidth. The invention is particularly beneficial when implemented over cable and DSL network access links with slow upstream feed rates.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates generally to Internet communications, and more particularly to priority schemes for transmitting packets from different communication sources across a packet switched network. [0002] Successful transmission over the same IP connection of both synchronous content such as voice and asynchronous content such as data requires careful scheduling, particularly if the offered packet load from the asynchronous source can meet or exceed the network capacity. This creates the possibility of filling most of the network channel bandwidth with data packets, thereby delaying or disrupting transmission of real-time voice conversation packets. If undesirable latency (i.e., delay) for the voice packets is not ameliorated, then the quality of voice content received at a destination may be deficient or in the worst case fragmented, garbled or unintelligible. [0003] For example, when one or more users initiate data traffic during a Voice over IP...

AI Technical Summary

Benefits of technology

[0008] The voice and data packets may be interleaved together for sending through a time division multiplexed transmission link in accordance with predetermined position guidelines that slow down the upstream data packet rate and speed up the upstream voice packet rate. Different combinations of interleaved voice and data packets help to alleviate packet congestion while maintaining priority for voice packets.

Problems solved by technology

This creates the possibility of filling most of the network channel bandwidth with data packets, thereby delaying or disrupting transmission of real-time voice conversation packets.

If undesirable latency (i.e., delay) for the voice packets is not ameliorated, then the quality of voice content received at a destination may be deficient or in the worst case fragmented, garbled or unintelligible.

For example, when one or more users initiate data traffic during a Voice over IP call, the data will interfere with the voice packets causing poor or disastrous voice quality at the listening destination.

This problem is often a result of limited bandwidth in network access links such as cable and DSL that have slow upstream feed rates.

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